The Population Center has 6 primary cores: (1) Primate facilities; (2) Tissue culture service; (3) Mass spectrometry; (4) Statistical services; (5) Bioengineering; and (6) Sexual behavior. It is devoted to studies of female primate neuroanatomy, particularly the hypothalamic-pituitary region and endocrinology; biochemical (including steroid and $ polypeptide) and cytogenetic studies of normal and adreno-cortical steroid pathways with mass spectrography; investigations of ovarian and adreno-cortical steroid pathways with mass spectrography; the biosocial problems of populations; and a combined psychosexual-endocrine evaluation of human male and female sexual behavior. BIBLIOGRAPHIC REFERENCES: 1) Ferin, M., I. Dyrenfurth, U. Schwartz and R.L. Vande Wiele. Effects of immunization with gonadal steroids on pregnancy and on the estrous and menstrual cycle in rodents and primates. Presented: Symposium on Immunization with Hormones in Reproductive Research - Bonn-Bad, Godesberg, Germany, March 21-22, 1975. p. 119-137. (North-Holland Pub. Co.); 2) Ferin, M., P.W. Carmel and R.L. Vande Wiele. The neuroendocrine regulation of LH secretion by estrogens in rhesus monkeys. In: Advances in Biosciences 15: 233-238, 1975.